With the government softening its stance against marijuana and recent state legislation to ease access, there is renewed interest in what the long-term impact of increased marijuana use might have on cigarette smoking. Even while many Americans express a greater openness to use of marijuana, the nation’s tolerance for tobacco use has been declining. Yet, a new National Institute on Drug Abuse (NIDA) study shows that making marijuana more available is likely to increase the number of cigarette smokers.
According to the report, smoking marijuana actually increases the pleasure of tobacco use and thereby makes it more likely that a person will become addicted to nicotine. There is an already-identified link between marijuana and tobacco use since the majority of marijuana users use both substances. Twenty percent of tobacco users started with marijuana, according to the researchers. The rates are even higher (33 percent) among black marijuana users.
In addition, the more often a person uses pot, the more likely it becomes that they will start smoking tobacco. One study found that weekly marijuana use was more apt to result in cigarette smoking compared to less frequent marijuana use. In short, using marijuana increases the likelihood that a person will start smoking cigarettes, and the more pot they use, the greater the likelihood that they will start smoking tobacco.
The NIDA study used laboratory rats to examine how using one substance influenced use of the other. The rats were exposed 10 times to THC, which is the psychoactive agent found in marijuana. After being exposed to THC they were given the opportunity to self-administer nicotine. As a control, another group of rats were allowed to self-administer nicotine without ever being exposed to THC.
Interestingly, the increased desire for nicotine was not a transitory result of marijuana exposure. For example, not only did rats self-administer greater amounts of nicotine after receiving THC compared to non-exposed rats, but their desire for nicotine was also longer-lasting and more intense.
At one point, rats were exposed to THC and then had to wait seven days before being given the opportunity to access nicotine, and yet their drive for it remained strong. The THC-exposed rats were still willing to work hard in order to self-administer nicotine a week after their last previous dose of THC. And it gets worse. The rats continued to exhibit an increased drive for nicotine 30 days out from their final exposure to THC.
The NIDA research suggests that as the nation opens its arms to increased marijuana use, it had best be prepared to welcome more tobacco smokers too. Marijuana use will not replace tobacco use – it will trigger more cigarette use. This may be good news for tobacco growers and cigarette manufacturers, but it’s bad news for public health officials.